The league has a total of 16 teams organized in two divisions, North and South. Teams play 114 games each season. Five teams in each division advance to a four-round postseason tournament that culminates in the Serie del Rey, a best-of-seven championship series between the two division champions. The Mexican League has two minor leagues of its own, the Liga Norte de México and Mexican Academy League.

Though founded in 1925, the league did not join the National Association of Professional Baseball Leagues (Minor League Baseball) until the 1950s, when it was designated a Double-A league. Some member teams entered player development contracts with teams in the National League at that time. Triple-A classification was granted in 1967.

The Mexican League was founded in 1925 by sportswriter Alejandro Aguilar Reyes and former baseball player Ernesto Carmona.[7] The league included six teams (74 Regimiento, México, Agrario, Nacional, Guanajuato and Águila). Puebla's 74 Regimiento won the initial league championship. Since then, the league has expanded to 16 teams, divided equally into a north and a south zone, the champions of which meet to contest a best-of-seven gameplayoff series. The season begins in mid-March with the playoffs running through mid-August.

Judges, under the doctrine of stare decisis, use the case Federal Baseball Club of Baltimore v. National League of Professional Baseball Clubs to maintain that the baseball leagues and commissioner are not violating anti-trust laws because they are not doing anything different from what was done when the previous holding was handed down. Included in the previous ruling was the fact that the baseball leagues at the time of the ruling could transmit information about their games via telegraph wires; radio and television are merely extensions of the type of coverage provided by the older medium. Further, because the leagues are only negotiating as agents for their member clubs, their actions in negotiating the television and radio broadcasts are essentially no different from their actions with telegraphs. Therefore, the previous decision can be maintained. Judges also have asserted that this the previous decision has not ever been objected to by Congress, in that no corrective legislation which would have overturned the ruling has ever been enacted, so it must also be of the opinion of Congress that baseball does not fall under the rules of the Sherman Antitrust Act (some judges have found differently, but final rulings have always overall held in favor of Organized Baseball).

The ruling went untested until the Mexican League was formed. Players who went to play in the Mexican League were blacklisted from Major League Baseball. One such player, Danny Gardella, was blacklisted because he had violated his contract and gone to play professional baseball in Mexico.

During 1948, Gardella brought a claim against Commissioner of Baseball Happy Chandler, the National League and American League, as well as their presidents (Ford Frick and Will Harridge, respectively). Gardella charged that they were engaged in interstate commerce because the defendants had made contracts with radio broadcasting and television companies that sent narratives or moving pictures of the games across state lines. MLB then settled with Gardella and offered all Mexican League jumpers amnesty, protecting the ambiguity of the antitrust protection.[8]

In 1949, Gardella won a major appeal against baseball's reserve clause in the federal courts. This successful appeal is recognized as the first major step towards baseball free agency, even though it was decades in the making.

In 1979, the Mexican Central League was absorbed into the expanded Liga Mexicana de Beisbol (Mexican Baseball League). The newly expanded league featured a 20-team circuit with four divisions. However, after a series of team bankruptcies, the Mexican League was reduced to 14 teams in two divisions.